iPhone - Pandora or Spotify? (or other?)

ArcticFox

We are going to be going out of town for the holidays and I want to have something good on my phone. 

-- I tried Spotify but now I think I need to pay for the membership to access anything.

-- I have Pandora, but if I need something like lullabies, I dont' want the commercials coming on

Any suggestions which one to go with?  Or another one?  I don't even know how much they cost to use.  Also with Pandora it wouldn't let me play anything back-to-back (like a same artist) but Spotify was allowing me to play the whole Tangled movie soundtrack, so that would be a bonus, but I haven't looked into how good their lullabies or other kids music is.